Diaphragm pump



March 17, 1953 JB JOHNSON DIAPHRAGM PUMP Filed Nov. 17

FIG. 3

ATTORNEY IN VEN TOR JB JOHNSON FIG- Patented Mar. 17, 1953 UNITED Pars NT ro.-F.-F1cE DIAPHRAGMTUM'P i JB Johnsonflliyler; 1".Tex., assignon of twenty-four {,rperzcent toWilford C. Thompson .andtwentyfourpercent .to Pickens vMorris, :bothof. .Tyler,

Tex.

-' Application-November 17, 1949, Serial- 'N0.l27;919

v 10,--Claims. 1

'Thisinvention relatestoi fluidpumps andmore particularly to a' 'diaphra'gmiitype' pump incor- -po1'ating -novel drive wand aoo'ntr ol features and being particularly -adapted' for use 'where' space is at a premium.

""Diaphrag-m type pumps are old and: well known and possess numerous advantages such as relatively low construction cost,--r'elatively -large 'capacity for r a igiven physical size, simplicityof structure and reliabilityin operation. This invention retainsall of the prior advanta'ges and :.uals units mayxbe convenientlyzstacked to provide a 'multiple tchamber pump.

It is a, further object of the invention to: provide 1 a: diaphragmpump which: may: beconveniently manufactured asa multi-stage pump in order-to producezrelatively highpressures whilestill maintaining the inherentadvantagesof aidiaphragm wpump.

- -@I'rrisaiurtheriobject-orrthe invention to provide :..:a ldiaphr'agmmump of relatively simple and :eco-

"nomicals construction IIiII WhiChI it I is unnecessary to '.:maintain close: 2 dimensional: tolerances: and

which: provides ready accessibility :forr2mainteanance-andsrepair when such becomes necessary.

if Furthertobjectsziand advantagesofthe present .ainventionr: will=:-.:be apparent? from:. .the; following descriptiont-takeniin conjunction -withltheaccompanying .drawings; wherein:

.rEig; 1. is va longitudinal sectional view showing the; internal structurexof the diaphragm pump of this-invention: and the. associated'rdriveisand con- .:.trol=mechanism;

Eig: 2,. a vtop plan view*' of: the pump 'shown' in Fig. l with the cover plate removed;

Fig. 3-, :a fragmentaryloneitudinalseotional view showing. a plurality otpumpunits.stacked-to provide. a. multiple-chamber pump;

-. Fig. 4, a, .gfrag-mentaryr longitudinal sectional v-.view J similar to Fig, 3: showing a, plurality of .stacked progressively :smallennnits-to providea multi-stageadiaphragm pump;

,.;'F,"ig.15,-a fragmentary view with parts in-section 2 for greater clarityshowi-ng a portion .of.the drive mechanismandassociated:control-means and, p v

Fig. 6, a sectional -view-showingthe detailsof oneof the valves incorporated in the diaphragm .of the pump.

With continued reference tothe drawingsthere isshownin Fig. 1 adiaphragmgpump;including a main pump "body. I til-which may .be'conveniently constructedin theform-of a relatively thick circular; plate":.although .th-is body-mayr-be of any form desired. :Bodylii is providedain itsupper faoe-witlra recesshaving ane-ang-ularly disposed peripheral wall i, the central-portion ofthebody l 0' being counterboredat rl 2 and I 3 for a purpose to be presently described. Acover; plate-14 is provided witha wfrustoaconical@recess I5 in its lower facewhich together with the recessin: the body l0 --constitutes the-rpump chamber. Cover plate M is adapted to be positioned on the-body -10 and be secured thereto byscrew threaded fastening means 'or the like 46.

1A diaphragm I 'Lof suitable flexible material. is

..-clamped between body It andcoverplate14 ad- -.jacent the periphery-thereof, this-diaphragm extending completely across the pump 1 chamber. and beingclamped to a reciprocating-valve plate 18 by .-a clamping plate l9 provided with a plurality. of .apertures -20: and. a-central. portion 2 I- havinga recess. thereinrfor apurpose to be presently described Clamping plate l91is.secured.tova1ve plate It by a plurality of screwthreadedfasteners .or the like 23.

Valve plate 13 'isprovidedwith a pluralityof apertures 24, these apertures terminating incoun- -.terbores zsadjacent... the upper. surface 0f. the plate. Positioned. in each of these. counterbores .is a valve 2 6. shown in detail in Fig. 6.

Valve.26 comprises a stamped sheet metalbody ,21 ofstepped construction, there being aplurality ,of .S10ts-. 0rapertures 28 therein to permit the passage offiuid through the valve. Valve body 2 lis so. formed as to; provide a centrally located aperture 2 9, the. sidewall of: which terminates inwardly of. the 'body Z'Lto provide .a valve :seat 30. .45

Positioneduponthis seat-is a valve member 3|;in

.theI'orm of a disc: whicnis normally held in :engagement withthe seat- -30 by a compression spring :32 engagin the 1va1ve-r member 3| 5:. and :the-bodyli. A portion of the bodyzl provides an annular flange 33swhich may-be conveniently utilizedto'secure the valve '26 in positionyinzthe valve plate I8. .This. operation is: accomplished by; seating the valve:.-26 in the: 'counterbore 25.

..there"=being; a ..p1ura1ity .of screw :threaded fasteners :zor r the like 3 lrpositioned:v around the counterbore with a portion of each head of the fasteners 34 engaging the flange 33 and the upper surface of the plate I8 to securely clamp the valve 26 in position within the counterbore 25.

Valve plate I8 is provided on its lower surface with a centrally located circular boss 35 having a generally hemispherical recess 36 therein, the outer surface of the boss 35 being provided with a tapered threaded portion 31 adapted to receive a taper threaded nut 38. This structure provides a convenient means for attaching the diaphragm l1, valve plate l8 and clamping plate l9 to the drive mechanism to be presently described.

In order to conveniently mount or support the pump body In and associated parts and also to house the driving mechanism there may be provided a tubular member 39 having a flange 40 at one end secured to pump body by screw threaded fastening means or the like 4|, the opposite end of tubular member 39 terminating in a flange 42 having apertures 43 therein for receiving fastening means to securely mount the pump upon a supporting structure.

The novel drive mechanism incorporated in this pump comprises a cup-shaped cylindrical member 44 slidably received within the tubular member 39 cylindrical member 44 also slidably receiving a second cup-shaped cylindrical member 45 to provide a telescoping assembly. Posi tioned within the members 44 and 45 and in engagement with their end walls is a compression spring 46 which serves to transmit compressive force from member 45 to member 44.

Member 44 is provided with an axially extending rod-like portion 41 terminating in a ball 48 received in the hemispherical recess 36 in boss 35. Ball 48 is loosely clamped in position by taper threaded nut 38 to provide a ball and socket joint.

Cylindrical member 45 terminates at its lower end in an axially extending rod-like portion 49 which is slidably received in an aperture 50 in end closure plate which may be secured in place in a counterbore 52 in the end flange 42 by screw threaded fastening means or the like 53. Aperture 50 together with the cylindrical inner wall of the tubular member 39 provides a guide means for the drive assembly. However, close manufacturing tolerances need not be maintained for these parts since all that is necessary is a relatively loose sliding fit.

In order to prevent leakage between the pump chamber and the interior of tubular member 39, a sealing diaphragm 54 may be clamped in counterbore l3 in pump body In by a clamping plate 55 secured by screw threaded fastening means or the like 55. Sealing diaphragm 54 is provided with a centrally located aperture received over the boss 35 and is clamped in position thereon by taper threaded nut 38. This structure provides an effective seal between the pump chamber and the interior of tubular member 39 and prevents any leakage of fluid therebetween.

In order to vent any fluid pressure which may build up within the telescoping cup-shaped members 44 and 45 and also to permit the introduction of lubricant thereto member 44 may be provided with a vent opening 51 and member 45 with a vent opening 58. Likewise, closure plate 5| may be provided with vent openings 59 whereby lubricant may be introduced to the assembly and fluid pressure vented therefrom.

The above described pum may be driven in any desired manner but for purposes of illustration only there is shown a drive shaft 60 having 4 a pulley 6| mounted thereon and engaged by a drive belt 62. Also mounted on shaft 60 is a cam 63 which engages a cam follower 64 secured to rod-like extension 49 on cup-shaped member by screw threaded fastening means or the like 65. Obviously if desired the rod 49 could be operated by a rocker arm engaging the end thereof or by a conventional crank and pitman arrangement and also rod 49 if desired might be connected directly to the piston of a reciprocating motor. Since the particular means for actuating the rod 49 forms no part of this invention, it is deemed unnecessary to illustrate or describe other than one conventional means.

The suction chamber of the pump of this invention is provided by the recess in the pump body It] and in order to permit the flow of fluid thereto there is provided a screw threaded bore 66 which may threadedly receive an inlet valve 61. Valve 61 is provided with a valve member 68 which is normally urged to closed position by a compression spring 69. However, upon upward movement of the diaphragm H to create a vacuum within the suction chamber the pressure of fluid on the outer surface of valve member 68 will move the same inwardly against the action of spring 69, thus permitting the flow of fluid to the suction chamber.

The recess |5 in the cover plate l4 provides a compression chamber and in order to conduct compressed fluid therefrom there is provided in the cover plate M a screw threaded bore 19 in which is threadedly received an outlet valve 1|. Valve 1| is provided with a valve member 12 which is normally held in closed position by a compression spring 13, this valve preventing flow of fluid from the exterior of the pump into the compression chamber but opening against the action of spring 13 to permit the flow of compressed fluid therefrom.

In order to insure return of the diaphragm l1 and associated parts to lowermost position there is provided a return spring 14 with one end positioned in reces 22 in clamping plate l9 and with the opposite end positioned in a recess 15 in cover plate I4.

In operation upon rotation of the shaft and associated cam 63, the rod 49 and cup-shaped member 45 will be reciprocated due to the engagement of cam 63 and cam follower 64. This reciprocatory movement will be transmitted in one direction to cup-shaped member 44 by compression spring 46 which will serve to move the valve plate l8, diaphragm I1 and clamping plate l9 upwardly in the pump chamber to compress fluid above the diaphragm and force the same outwardly through outlet valve 1|. At the same time a partial vacuum will be created below the diaphragm causing fluid to flow into the suction chamber through valve 61. Upon return movement of the diaphragm under the action of spring 14 the valve members 3| in valves '26 will open against the action of springs 32 to allow fluid in the suction chamber to flow upwardly through slots 28 into the compression chamber thus recharging the same with fluid to permit repetition of the pumping cycle.

Obviously the compression spring 46 may be so calibrated that the pressure developed in the compression chamber will be governed thereby since if such pressure exceeds the compression strength of spring 46 this spring will yield and the diaphragm and associated parts will remain stationary until cup-shaped member 45 returns to its lowermost position at which time return spring ag-cameo chamber becomes filled *orpartially filled with liquid or other comparatively incompressible substance whereby a=positive movement of thediaphragm wouldresult-in damage to the parts with pos's-iblerupture or the diaphragm-or-breakageof the associated elements.

Since-it is often'desirable'to discontinue-operation or the pump-without stopping-"the mochanism which supplies motive power thereto and also since-itis often highly desirable-to provide means whereby the capacity of the pump maybe -varied-;a'- simple 'efficient and novel control mechanismis provided which is'shownin detail in and appliedto'the pump assembly-inFiggl.

Thiscontr'olmechanism comprise a bell crank lever I 6-which maybe conveniently-pivoted at T! on cars I9extending from the wall of-the tubular -member'39; a portion ofthebell-crainkflevefl6 extendingthrough aperture "I9 inthe wall ofthe tubular member 39. The I inner end ofthe-"bell cranklever 194s provided with a; yoke 89, the ar-ms thereof being disposed-on *each side or the extension" 47, the yoke arms- 'terminating in'= enlarged portions-=9 I providing bearing surfacesto engage the lower surface-of taper threaded nut- 38. The oppo'siteendof bell cranklever 'lfi is provided. with an aperture'd portion ilz adaptedto receive an operating or control-wire 83 which is clamped in position by; a screw threaded fastening means or the like 84. The control wire-93 mayextend through-a fiexiblesheath95 to a point-convenient -to 'the operator, the wire 83 being provided'with -a' finger engaging .knob (not shown) which'may be utilized for controlling operation of the pump. Sheath 85 may be secured in position by *oneor more sheet metal clips 89 fixed in place by screw threaded-fastening means or the like 81.

Upon=operation=of control'wire-83 to rotate'the bell crank-lever 1 6 clockwise as viewed Fig.5, the enlarged portion" 8 l will bear against thenut 38 and raise the diaphragm I1 and-'- associated -parts'to-"uppermost *po'sition thereby --preventing reciproc'ation' 0f the same under the action of "rod 49' and compression spring dfi. 7 Thiswill result in v 'reducing-the pump capacityto-zero and the pump awillremainJ in inoperative condition --until 'wire Z83 is actuated to/move :bell crank lever- 16 in counterclockwise direction w-hereupon the diaphragrn I I and--associa-ted parts will be-'reciprooated through -a-- path-of traveldepending upon ithe'position of enlarged portion 8 I It the-move- 'ment of the --bell 'crank lever E is sufiicient to move the enlarged portion 8I -entire1y-out of contact-with nut -38 then the diaphragm I I and associated parts-will move through their full path of travel. and the pump =willdeliver its maximum icapacity whereas ifv the enlarged portion 8 I occuspies.somezintermediate position this-will serve to blockv downward movement of the nut-39 and dia- ::phragm SI 1 whereby the path of travel will besome intermediate value between maximum: arid zero. Thisustructure results insprovidingsian"infinite variation. in. the. capacity of the 1 pump between --.;zero.andhma'ximum and. obviously means will'be provided to properly clamp the control wire 83' in order to retainithebellcrankslever' I6-and --"en. -larged portion 8 I in the desired position.

.Obviously variousrmodifications of this control .-,.mechanismv may be employed such asa camin engagement with-the nut 38; the :cam having" .a mproperscontour to. accomplish the desired-yaria- -1- tion-"in diaphragm'movement. "The basic principle, however, would be the same regardless of what specific mechanism was employed and the structure'disclosed inFig. 5 is byway of illustration only.

The-pump structure above described isreadily adapted for use in a -multi'ple pump structure such'as that shown-in detail in Fig. B and in which the pump body I9 is identical withthat shown in 'Fig. 1' and in which the-cover plate-B8 is 'slightly modifiedfrom-thecover plate I I. shown in" Fig. 1. In-"this modification the cover plate 98 is provided with a central bore 99 and a-counterbore 9 9 which bore and counterbore serves to receive the mechanism linking adjacent units "of the pump: together. Clamping plate I9 is provided-*at its' 'ce'nterwith -a boss' 9| similar to 'the boss 35on-the valve'p1ate-l8. boss 9I- beingprornecting rod 95,- the ball 94 being loosely clamped in positionby a taper threaded nut 99 engaging the threads 93. Nut 99 likewise serves to clampia sealing diaphragm 91- in position, theouterportion of this diaphragm being clamped in-counterbore 99 byaclamping plate 98 and screw threaded fastening means or the'like 99. 'This' diaphragm serves to effectually seal the'bore 89' against the passage or fluid from the compression chamber of the pump. The cover plate88 is provided with .a-screw threaded bore- I99 for receiving outlet valve I I- identical with that provided in the pump 'shown'in -F ig. 1. This comprises one-unit of the multiple pump and operates to receive and discharge fluid under pressure in-exactly the manner above described'in connectionwith the 'operation of the pump of Fig. 1.

'I'hesecond unit of the pump is identicalwith that just described, this pump being operatively connected to the first unit by the connecting rod-'95, the upper end of which is provided 'with'a ball-likeconnecting'member I 9| which .isreceived'in the'hemispherical recess 36 of the boss 35. -As many units as desired may be stacked "one on the other, the only limiting factor being space andthe operating power available, the up- -per or finalunit-being identical with the pump shown in Fig. 1, the cover plate I4 serving to terminate the assembly with the fastening means "Ifi beingielongated andex-tending through the "entire assemblyto the pump body l9 whereby "the complete stack is accordingly clamped in operative relationship. This pump may beutilizedto 'haridlea plurality of different fluids for different purposes or may serve to supply a single fluid at anincreasedvolume.

The pump'of this invention also adapts itself -'to providing'a multi-stage pump, the details of which'are-shown-in Fig. 4. In this modifica- --tion the pump body I9 is identical with that describedin connection with the'previous modifications' and the cover plate I92 for the first stage. of 1 the pump is provided with a central aperture and sealing mechanism as described in connection with the modification-of. Fig; 3,.this

;cover'plate.being further modified to provide .screw threaded bores I93 for threadedly receivingdischarge valves I94 which are similar to dischargeuvalves 'Il previously described.

:The-pumpbody I95 for the second stage of the qgstioned-to register. with: the bores I93 in-the-cover plate I02 when the body I and plate I02 are positioned in stacked relationship, ports I06 serving to receive high pressure fluid from the compression chamber of the first stage of the pump and deliver this fluid to the suction chamber of the second stage. The cover plate I02 for the second stage is identical with the cover plate I02 for the first stage with the exception that the diameter thereof is less to correspond with the diameter of the pump body I05 whereby the volume of the pump chamber is reduced since the volume of the fluid received in this second stage is less than the volume of fluid received in the suction chamber of the first stage, this reduction in volume arising due to the compression of the fluid in the first stage. Likewise, the pump body I05 of the third stage is of reduced diameter to correspond with the diameter of the cover plate I02 of the second stage whereby the volume of the pump chamber in the third stage is still further reduced. The cover plate I0! is similar to cover plate I4 except for size and is provided with a central recess I4 to receive one end of return spring '15 and is also provided with a screw threaded bore to receive discharge or outlet valve II.

The operation of the three stage pump is similar to that described above in connection with the modification shown in Fig. 3 except that fluid is received into the pump through inlet valve B'l' whereupon it is compressed in the first stage and discharged therefrom into the second stage where it is further compressed and discharged into the third stage, the third stage providing the final compression and discharge through the outlet valve 1|.

Obviously the control mechanism described in connection with the modification of Fig. 1 is equally applicable to the modifications of Figs. 3 and 4 and together with these modifications provides a very efiicient and versatile pump mechanism. Due to the use of diaphragm type pistons very little machine work is required in fabricating the device and practically no close machine tolerances need be adhered to. Consequently, a very low cost construction is possible and the unit will operate to deliver a maximum quantity of fluid and yet occupy a minimum of space. Likewise, in View of the particular nature of the construction a relatively simple control mechanism is possible whereby the output of the pump may be varied from zero to maximum without in any way effecting the operation of the drive mechanism and likewise it has been rendered very convenient to provide means for preventing damage to the pump due to the presence of liquid or other relatively incompressible fluid in the pump chamber.

It will be obvious to those skilled in the art that various changes may be made in the invention without departing from the spirit and scope thereof and therefore the invention is not limited by that which is shown in the drawings and described in the specification but only as indicated in the appended claims.

What is claimed is:

l. A diaphragm pump comprising a body, a cover member secured to said body, said body and cover member being recessed to form a pump chamber, a diaphragm between said body and said cover member and extending across said chamber, an inlet valve in said body, an outlet valve in said cover member, a valve plate secured to said diaphragm, valves in said valve plate for controlling the flow of fluid from one side of said diaphragm to the other, a support for said pump comprising a tubularmember secured to said body, sealing means between said chamber and the interior of said tubular member, a drive mechanism for reciprocating said diaphragm comprising a first cup-shaped member slidably disposed in said tubular member, a second cupshaped member telescopically received within said first cup-shaped member, a calibrated compression spring disposed within said cup-shaped members, means connecting said first cup-shaped member and said Valve plate, means for reciprocating said second cup-shaped member whereby said diaphragm will be reciprocated through said spring, the pressure developed in said chamber being dependent upon the compression strength of said spring and a return spring engaging said diaphragm and said cover member.

2. A diaphragm pump comprising a body, a cover member secured to said body, a recess in said body and said cover member forming a pump chamber, a diaphragm clamped between said body and said cover member and extending across said chamber, an inlet valve in said body, an outlet valve in said cover member, a valve plate secured to said diaphragm, valves in said valve plate for controlling the flow of fluid from one side of said diaphragm to the other side, a support for said pump comprising a tubular member secured to said body, sealing means be tween said chamber and the interior of said tubular member, a drive mechanism for reciproeating said diaphragm comprising a first member slidably disposed in said tubular member, a second member slidably disposed in said tubular member and spaced from said first member, a

calibrated compression spring disposed between said members, means connecting said first member and said valve plate, means for reciprocating said second member whereby said diaphragm will be reciprocated through said spring, the pressure developed in said chamber being dependent upon the compression strength of said spring and a return spring engaging said diaphragm and said cover member.

3. A diaphragm pump comprising a body, a cover member secured to said body, a recess in said body and said cover member forming a pump chamber, a diaphragm clamped between said body and said cover member and extending across said chamber, an inlet valve in said body, an outlet valve in said cover member, a valve plate secured to said diaphragm, valves in said valve plate for controlling the flow of fluid from one side of said diaphragm to the other side, a support for said pump comprising a tubular member secured to said body, sealing means between said chamber and the interior of said tubular member, a drive mechanism for reciprocating said daiphragm comprising a first member slidably disposed in said tubular member, a second member slidably disposed in said tubular member and spaced from said first member, a calibrated compression spring disposed between said members, means connecting said first member and said valve plate, means for reciprocating said second member whereby said diaphragm will be reciprocated through said spring, the pressure developed in said chamber being dependent upon the compression strength of said spring. 4. A diaphragm pump as defined in claim 1 in which said sealing means comprises a diaphragm clamped to said body and to said valve plate in fluid tight relationship. I

5. A diaphragm pump comprising a body. and

a cover member recessed to provide a pump chamber therebetween, a diaphragm within said chamber, an inlet valve in said body, an outlet valve in said cover member, valve means associated with said diaphragm for controlling the flow of fluid from one side of said diaphragm to the other side, a support for said pump comprising a tubular member secured to said body, means for reciprocating said diaphragm comprising a first cup-shaped member slidably disposed in said tubular member, a second cup-shaped member telescopically received within said first cupshapcd member, a calibrated compression spring disposed within said cup-shaped members, means connecting said first cup-shaped member and said diaphragm, means for reciprocating said second cup-shaped member whereby said diaphragm may be reciprocated by said spring, the pressure developed in said chamber being dependent upon the compression strength of said spring.

6. A diaphragm pump comprising a body and a cover member recessed to provide a pump chamber therebetween, a diaphragm within said chamber, yieldable means for reciprocating said diaphragm and a control means for said pump comprising a pivotally mounted bell crank lever, one end thereof terminating in a yoke, enlarged bearing portions upon said yoke constructed and arranged to engage said diaphragm, a control wire secured to the opposite end of said bell crank lever whereby upon operation of said control wire to pivot said bell crank lever said bearing portions will engage said diaphragm to prevent movement thereof or engage said diaphragm to permit limited movement thereof, said control means being effective to control the capacity oi said pump between zero and maximum.

7. A multiple diaphragm pump comprising a body and a cover member recessed to provide a pump chamber therebetween, a diaphragm disposed in said chamber, a second body and cover member providing a second pump chamber therebetween, a second diaphragm disposed in said second pump chamber, a third pump body and cover plate providing a third pump chamber therebetween, a third diaphragm disposed in said third pump chamber, said pump bodies and cover members being secured together in stacked relationship, a connecting rod connecting said first and second diaphragms, a second connecting rod connecting said second and third diaphragm, sealing means between said first pump chamber and said second pump. chamber, sealing means between said second pump chamber and said third pump chamber and yieldable means for reciproeating said diaphragms whereby the pressure developed in each pump chamber will be dependent upon the compression strength of said yieldable means.

8. A multiple diaphragm pump as defined in claim '7 including control means for reducing the output of said pump to zero or for infinitely varying the output between zero and maximum.

9. A multiple stage diaphragm pump comprising a body and cover member recessed to provide a pump chamber therebetween, a diaphragm disposed in said chamber, a second pump body and a cover member providing a pump chamber of reduced volume therebetween, a second diaphragm in said second chamber, a third pump body and cover member providing a third pump chamber therebetween of still further reduced volume, a third diaphragm disposed in said third chamber, connecting rods connecting said first and second diaphragm, a second connecting rod connecting said second and third diaphragms, sealing means between said first and second pump chambers, sealing means between said second and third pump chambers, valved ports connecting said first and second pump chambers, valved ports connecting said second and third pump chambers, an inlet valve to said first chamber, an outlet valve from said third chamber and yieldable means for reciprocating said diaphragms whereby the pressure developed in said third pump chamber is dependent upon the compression strength of said yieldable means.

10. A multiple diaphragm pump as defined in claim 9 including control means for reducing the output of said pump substantially to zero or for infinitely varying the output substantially between zero and maximum.

JB JOHNSON.

REFERENCES CITED The following references are of record in the 

